Underfeed stoker furnace



March 18 1924.

1,487,073v y J. H. RQACH Filed Aug. 20, `1920 'l m l lllll ETIIIIVII lwm! Patented Mar., l, 1924,

lgthtf JOSEPH H. ROACH, OF BROOKLINE, PENNSYLVANIA; WALTER T. R-ACH EXCUTOBOF SAID JOSEPH H. BOAC-f, DECEASED.

Unnnarnsn s'ronnn scannen.

Application filed August 20, 1920.

grate-bars from the foot ends to the headends thereof and discharged into the retort in a heated condition, and air from the low pressure air chamber is discharged through narrow openings or interstices between the sides of adjacent grate-bars, thereby serving to aid combustion and lower the coking zone in the retort and at the same time tending to reduce the temperature of the gratebars and prolong the life thereof, all as will be hereinafter more fully described and claimed.

Throughout the description and claim the term head end refers to the extremity of a 1 grate bar adjacent the retort, the term foot end referring to the opposite end which is adjacent the ashv pit. V

Referring to the accompanying drawings, which are made a part hereof and on which similar reference characters indicate similar parts,

Figure 1 is a fragmentary horizontal section of a furnace showing the grate structure and retort in plan. A

Figure 2 a cross section through the same.

In said drawings-the portions marked A represents the bed or-foundation of the furnace, B the grate-bars, and C the retort or fluid channel, all of which parts are in the main of a type in common use and substantially the same as shownv in Letters Patent No. 1,346,465 granted to me on July 13, 1920. Y Y

ln my present construction, however, air comes through a main air duct 10 into the high pressure air chambers 11 positioned under the foot ends of the hollow gratebars B and communicating therewith through a hol- Serial No. 404,738.

low wall or conduit 18 on which said grate bars rest at their foot ends. The passage of the air from the main air duct 10 to the high pressure chambers 11 is controlled by dampers or gates 1li. A portion of the air from the high pressure chambers 11 is adapted to pass into the low pressure chamber 15 under the grate-bars, the amount of air so passing being controlled by dampers 16 positioned in openings between said chambers 11 and 15 as shown.

T he grate-bars B are mounted so that alternate grate-bars will reciprocate, being connected to rock-shafts 17 as is common and illustrated in my above mentioned 4Letters Patent` The head ends of said gratebars are formed with tuyre openings 18 through which the air passes into the retort C and air passes from the low pressure chamber 15 through the interstices 19 between said grate-bars into the fuel thereon. By this means the air before going into the retort is heated to a Very high temperature in its passage through the grate-bars 12 and 'because of said high temperature not only Afacilitates combustion of the coal in the retort but serves to lower the zone ofignition thus increasing the coking capacity of the retort and the furnace. At the same time,

lthe air passing through said grate-bars has the retort, grates at opposite sides of the retort each comprising spaced hollow gratebars open at both ends, said grate-bars communicating at one end with the retort, high pressure chambers in the foundation parallel to said retort and open at the top, conduits supported at the outer side of said high pressure nearly across the same whereby passages are provided leading to a low pressure chamber beneath the grates and the retort, said conchambers and extending duits opening at their.1 upper ends into said my hand and seal at Philadelphia, Penusyh grate-hars, and pivoted dempers extending Vania, this 19th day of August, A. D. nineperaliel to said retort between the adjacent teen hundred and twenty.

mier Wells of the conduits and the high JOSEPH H. ROACH [Ls] pressure chambers respectively, substan- 1\\"Vtnesses: tially as set forth. JOSEPH C. LAIRD,

,in Witness whereof, I have hereunto set l). E. SMlTH. 

